Actually, the AC Freezer 7 Pro is quite a decent cooler, and C2D CPUs put out less heat than Athlon 64 x2s and Pentium Ds. Assuming you have good case ventilation (SYS temp within a few degrees C of ambient room temp), I suspect your cooler is not quite fully installed. This is common, due to the poor design of the 4-pin retention system. You need to make sure all 4 pins are completely through the MB, which in practice is very difficult if the MB is already installed in the case. Thus, 4-pin coolers should be installed before the MB is mounted in the case. Also, the arrows on top of the pins are for *quick-release*, so you need to make sure each pin is turned completely in the direction opposite the arrow on top before pushing it down into the MB.
Section 2.5 onward in this post may be helpful: http://www.tomshardware.com/forum/194385-31-part-assembly#t1184072